• They are active listeners.
• They are engaged with the material.
• They are receptive of feedback.
• They are open to difficulty.

• It feels difficult because you are constantly receiving feedback, and so you are constantly adapting and perfecting the material.

• The skills we wish to obtain is often a difficult one.
• We want challenging but possible lessons based on current level of skill.

• Consistent effort > cramming => for durable knowledge

Depending on how you structure your code, sometimes you’ll be able to omit semicolons at the end of lines. For now, you’ll want to include them just as we do.

• + (addition)
• - (subtraction)
• asterisk (multiplication)
• / (division)
• % (modulo)

• PEMDAS : Parentheses, Exponents, Multiplication, Division, Modulo, Addition, Subtraction.
• To force a specific order of operation, use the group operator ( ) around a part of the expression.

• Whenever you have a smaller number % a larger number, the answer will just be the initial small number. console.log(7 % 10) // => 7;

• can be wrapped by either single or double quotation marks, best to choose one and stick with it for consistency.
• If your string contains quotation marks inside, can layer single or double quotation marks to allow it to work. “That’s a great string”; (valid) ‘Shakespeare wrote, “To be or not to be”’; (valid) ‘That’s a bad string’; (invalid)
• Alt. way to add other quotes within strings is to use template literals. `This is a temp’l’ate literal ${function}` // use ${} to invoke functions within.
• .length : property that can be appended to data to return the length.
• empty strings have a length of zero.
• indices : indexes of data that begin at 0, can call upon index by using the bracket notation [ ]. console.log(“bootcamp”[0]); // => “b” console.log(“bootcamp”[10]); // => “undefined” console.log(“boots”[1 * 2]); // => “o” console.log(“boots”[“boot”.length-1]); // => “t”
• we can pass expressions through the brackets as well since JS always evaluates expressions first.
• The index of the last character of a string is always one less than it’s length.
• indexOf() : method used to find the first index of a given character within a string. console.log(“bagel”.indexOf(“b”)); // => 0 console.log(“bagel”.indexOf(“z”)); // => -1
• if the character inside the indexOf() search does not exist in the string, the output will be -1.
• the indexOf() search will return the first instanced index of the the char in the string.
• concatenate : word to describe joining strings together into a single string.

• Logical Operators (B_oolean Operators_) are used to establish logic in our code.
• ! (not) : reverses a Boolean value. console.log(!true); // => false console.log(!!false); // => false
• Logical Order of Operations : JS will evaluate !, then &&, then ||.
• Short-Circuit Evaluation : Because JS evalutes from left to right, expressions can “short-circuit”. For example if we have true on the left of an || logical comparison, it will stop evaluating and yield true instead of wasting resources on processing the rest of the statement. console.log(true || !false) // => stops after it sees “true ||”

• > (greater than)
• < (less than)
• >= (greater than or equal to)
• <= (less than or equal to)
• === (equal to)
• !== (not equal to)

• We initialize a variable by using the let keyword and a = single equals sign (assignment operator). let bootcamp = “App Academy”; console.log(bootcamp); // “App Academy”
• JS variable names can contain any alphanumeric characters, underscores, or dollar signs (cannot being with a number).
• If you do not declare a value for a variable, undefined is automatically set. let bootcamp; console.log(bootcamp); // undefined
• We can change the value of a previously declared variable (let, not const) by re-assigning it another value.
• let is the updated version of var; there are some differences in terms of hoisting and global/block scope

• In general, any nonsensical arithmetic will result in NaN ; usually operations that include undefined.

• Function Declaration : Process when we first initially write our function.
• Includes three things:
• Name of the function.
• A list of parameters ()
• The code to execute {}
• Function Calls : We can call upon our function whenever and wherever* we want. (*wherever is only after the initial declaration)
• JS evaluates code top down, left to right.
• When we execute a declared function later on in our program we refer to this as invoking our function.
• Every function in JS returns undefined unless otherwise specified.
• When we hit a return statement in a function we immediately exit the function and return to where we called the function.
• When naming functions in JS always use camelCase and name it something appropriate.

• Parameters : Comma seperated variables specified as part of a function’s declaration.
• Arguments : Values passed to the function when it is invoked.
• If the number of arguments passed during a function invocation is different than the number of paramters listed, it will still work.
• However, is there are not enough arguments provided for parameters our function will likely yield Nan.

• Single-line comments — To include a comment that is limited to a single line, precede it with //
• Multi-line comments — In case you want to write longer comments between several lines, wrap it in /* and */ to avoid it from being executed

• var — The most common variable. It can be reassigned but only accessed within a function. Variables defined with var move to the top when the code is executed.
• const — Can not be reassigned and not accessible before they appear within the code.
• let — Similar to const, the let variable can be reassigned but not re-declared.

• Numbers — var age = 23
• Variables — var x
• Text (strings) — var a = "init"
• Operations — var b = 1 + 2 + 3
• True or false statements — var c = true
• Constant numbers — const PI = 3.14
• Objects — var name = {firstName:"John", lastName:"Doe"}

• concat() — Join several arrays into one
• indexOf() — Returns the first position at which a given element appears in an array
• join() — Combine elements of an array into a single string and return the string
• lastIndexOf() — Gives the last position at which a given element appears in an array
• pop() — Removes the last element of an array
• push() — Add a new element at the end
• reverse() — Sort elements in a descending order
• shift() — Remove the first element of an array
• slice() — Pulls a copy of a portion of an array into a new array
• sort() — Sorts elements alphabetically
• splice() — Adds elements in a specified way and position
• toString() — Converts elements to strings
• unshift() —Adds a new element to the beginning
• valueOf() — Returns the primitive value of the specified object

• + — Addition
• - — Subtraction
• * — Multiplication
• / — Division
• (...) — Grouping operator, operations within brackets are executed earlier than those outside
• % — Modulus (remainder )
• ++ — Increment numbers
• -- — Decrement numbers

• == — Equal to
• === — Equal value and equal type
• != — Not equal
• !== — Not equal value or not equal type
• > — Greater than
• < — Less than
• >= — Greater than or equal to
• <= — Less than or equal to
• ? — Ternary operator

• && — Logical and
• || — Logical or
• ! — Logical not

• & — AND statement
• | — OR statement
• ~ — NOT
• ^ — XOR
• << — Left shift
• >> — Right shift
• >>> — Zero fill right shift

• alert() — Output data in an alert box in the browser window
• confirm() — Opens up a yes/no dialog and returns true/false depending on user click
• console.log() — Writes information to the browser console, good for debugging purposes
• document.write() — Write directly to the HTML document
• prompt() — Creates a dialogue for user input

• decodeURI() — Decodes a Uniform Resource Identifier (URI) created by encodeURI or similar
• decodeURIComponent() — Decodes a URI component
• encodeURI() — Encodes a URI into UTF-8
• encodeURIComponent() — Same but for URI components
• eval() — Evaluates JavaScript code represented as a string
• isFinite() — Determines whether a passed value is a finite number
• isNaN() — Determines whether a value is NaN or not
• Number() —- Returns a number converted from its argument
• parseFloat() — Parses an argument and returns a floating-point number
• parseInt() — Parses its argument and returns an integer

• for — The most common way to create a loop in JavaScript
• while — Sets up conditions under which a loop executes
• do while — Similar to the while loop but it executes at least once and performs a check at the end to see if the condition is met to execute again
• break —Used to stop and exit the cycle at certain conditions
• continue — Skip parts of the cycle if certain conditions are met

• \' — Single quote
• \" — Double quote

• \\ — Backslash
• \b — Backspace
• \f — Form feed
•  — New line
•  — Carriage return
•  — Horizontal tabulator
• \v — Vertical tabulator

• charAt() — Returns a character at a specified position inside a string
• charCodeAt() — Gives you the Unicode of a character at that position
• concat() — Concatenates (joins) two or more strings into one
• fromCharCode() — Returns a string created from the specified sequence of UTF-16 code units
• indexOf() — Provides the position of the first occurrence of a specified text within a string
• lastIndexOf() — Same as indexOf() but with the last occurrence, searching backward
• match() — Retrieves the matches of a string against a search pattern
• replace() — Find and replace specified text in a string
• search() — Executes a search for a matching text and returns its position
• slice() — Extracts a section of a string and returns it as a new string
• split() — Splits a string object into an array of strings at a specified position
• substr() — Similar to slice() but extracts a substring depending on a specified number of characters
• substring() — Also similar to slice() but can’t accept negative indices
• toLowerCase() — Convert strings to lower case
• toUpperCase() — Convert strings to upper case
• valueOf() — Returns the primitive value (that has no properties or methods) of a string object

• e — Evaluate replacement
• i — Perform case-insensitive matching
• g — Perform global matching
• m — Perform multiple line matching
• s — Treat strings as a single line
• x — Allow comments and whitespace in the pattern
• U — Ungreedy pattern

• [abc] — Find any of the characters between the brackets
• [^abc] — Find any character which is not in the brackets
• [0-9] — Used to find any digit from 0 to 9
• [A-z] — Find any character from uppercase A to lowercase z
• (a|b|c) — Find any of the alternatives separated with |

• . — Find a single character, except newline or line terminator
• \w — Word character
• \W — Non-word character
• \d — A digit
• \D — A non-digit character
• \s — Whitespace character
• \S — Non-whitespace character
• \b — Find a match at the beginning/end of a word
• \B — A match not at the beginning/end of a word
• \0 — NUL character
•  — A new line character
• \f — Form feed character
•  — Carriage return character
•  — Tab character
• \v — Vertical tab character
• \xxx — The character specified by an octal number xxx
• \xdd — Character specified by a hexadecimal number dd
• \uxxxx — The Unicode character specified by a hexadecimal number XXXX

• n+ — Matches any string that contains at least one n
• n* — Any string that contains zero or more occurrences of n
• n? — A string that contains zero or one occurrence of n
• n{X} — String that contains a sequence of X n’s
• n{X,Y} — Strings that contain a sequence of X to Y n’s
• n{X,} — Matches any string that contains a sequence of at least X n’s
• n$ — Any string with n at the end of it
• ^n — String with n at the beginning of it
• ?=n — Any string that is followed by a specific string n
• ?!n — String that is not followed by a specific string ni

• MAX_VALUE — The maximum numeric value representable in JavaScript
• MIN_VALUE — Smallest positive numeric value representable in JavaScript
• NaN — The “Not-a-Number” value
• NEGATIVE_INFINITY — The negative Infinity value
• POSITIVE_INFINITY — Positive Infinity value

• toExponential() — Returns the string with a rounded number written as exponential notation
• toFixed() — Returns the string of a number with a specified number of decimals
• toPrecision() — String of a number written with a specified length
• toString() — Returns a number as a string
• valueOf() — Returns a number as a number

• E — Euler’s number
• LN2 — The natural logarithm of 2
• LN10 — Natural logarithm of 10
• LOG2E — Base 2 logarithm of E
• LOG10E — Base 10 logarithm of E
• PI — The number PI
• SQRT1_2 — Square root of 1/2
• SQRT2 — The square root of 2

• abs(x) — Returns the absolute (positive) value of x
• acos(x) — The arccosine of x, in radians
• asin(x) — Arcsine of x, in radians
• atan(x) — The arctangent of x as a numeric value
• atan2(y,x) — Arctangent of the quotient of its arguments
• ceil(x) — Value of x rounded up to its nearest integer
• cos(x) — The cosine of x (x is in radians)
• exp(x) — Value of Ex
• floor(x) — The value of x rounded down to its nearest integer
• log(x) — The natural logarithm (base E) of x
• max(x,y,z,...,n) — Returns the number with the highest value
• min(x,y,z,...,n) — Same for the number with the lowest value
• pow(x,y) — X to the power of y
• random() — Returns a random number between 0 and 1
• round(x) — The value of x rounded to its nearest integer
• sin(x) — The sine of x (x is in radians)
• sqrt(x) — Square root of x
• tan(x) — The tangent of an angle

• Date() — Creates a new date object with the current date and time
• Date(2017, 5, 21, 3, 23, 10, 0) — Create a custom date object. The numbers represent a year, month, day, hour, minutes, seconds, milliseconds. You can omit anything you want except for a year and month.
• Date("2017-06-23") — Date declaration as a string

• getDate() — Get the day of the month as a number (1-31)
• getDay() — The weekday as a number (0-6)
• getFullYear() — Year as a four-digit number (yyyy)
• getHours() — Get the hour (0-23)
• getMilliseconds() — The millisecond (0-999)
• getMinutes() — Get the minute (0-59)
• getMonth() — Month as a number (0-11)
• getSeconds() — Get the second (0-59)
• getTime() — Get the milliseconds since January 1, 1970
• getUTCDate() — The day (date) of the month in the specified date according to universal time (also available for day, month, full year, hours, minutes etc.)
• parse — Parses a string representation of a date and returns the number of milliseconds since January 1, 1970

• setDate() — Set the day as a number (1-31)
• setFullYear() — Sets the year (optionally month and day)
• setHours() — Set the hour (0-23)
• setMilliseconds() — Set milliseconds (0-999)
• setMinutes() — Sets the minutes (0-59)
• setMonth() — Set the month (0-11)
• setSeconds() — Sets the seconds (0-59)
• setTime() — Set the time (milliseconds since January 1, 1970)
• setUTCDate() — Sets the day of the month for a specified date according to universal time (also available for day, month, full year, hours, minutes etc.)

• attributes — Returns a live collection of all attributes registered to an element
• baseURI — Provides the absolute base URL of an HTML element
• childNodes — Gives a collection of an element’s child nodes
• firstChild — Returns the first child node of an element
• lastChild — The last child node of an element
• nextSibling — Gives you the next node at the same node tree level
• nodeName —Returns the name of a node
• nodeType — Returns the type of a node
• nodeValue — Sets or returns the value of a node
• ownerDocument — The top-level document object for this node
• parentNode — Returns the parent node of an element
• previousSibling — Returns the node immediately preceding the current one
• textContent — Sets or returns the textual content of a node and its descendants

• appendChild() — Adds a new child node to an element as the last child node
• cloneNode() — Clones an HTML element
• compareDocumentPosition() — Compares the document position of two elements
• getFeature() — Returns an object which implements the APIs of a specified feature
• hasAttributes() — Returns true if an element has any attributes, otherwise false
• hasChildNodes() — Returns true if an element has any child nodes, otherwise false
• insertBefore() — Inserts a new child node before a specified, existing child node
• isDefaultNamespace() — Returns true if a specified namespaceURI is the default, otherwise false
• isEqualNode() — Checks if two elements are equal
• isSameNode() — Checks if two elements are the same node
• isSupported() — Returns true if a specified feature is supported on the element
• lookupNamespaceURI() — Returns the namespace URI associated with a given node
• lookupPrefix() — Returns a DOMString containing the prefix for a given namespace URI if present
• normalize() — Joins adjacent text nodes and removes empty text nodes in an element
• removeChild() — Removes a child node from an element
• replaceChild() — Replaces a child node in an element

• getAttribute() — Returns the specified attribute value of an element node
• getAttributeNS() — Returns string value of the attribute with the specified namespace and name
• getAttributeNode() — Gets the specified attribute node
• getAttributeNodeNS() — Returns the attribute node for the attribute with the given namespace and name
• getElementsByTagName() — Provides a collection of all child elements with the specified tag name
• getElementsByTagNameNS() — Returns a live HTMLCollection of elements with a certain tag name belonging to the given namespace
• hasAttribute() — Returns true if an element has any attributes, otherwise false
• hasAttributeNS() — Provides a true/false value indicating whether the current element in a given namespace has the specified attribute
• removeAttribute() — Removes a specified attribute from an element
• removeAttributeNS() — Removes the specified attribute from an element within a certain namespace
• removeAttributeNode() — Takes away a specified attribute node and returns the removed node
• setAttribute() — Sets or changes the specified attribute to a specified value
• setAttributeNS() — Adds a new attribute or changes the value of an attribute with the given namespace and name
• setAttributeNode() — Sets or changes the specified attribute node
• setAttributeNodeNS() — Adds a new namespaced attribute node to an element

• closed — Checks whether a window has been closed or not and returns true or false
• defaultStatus — Sets or returns the default text in the status bar of a window
• document — Returns the document object for the window
• frames — Returns all <iframe> elements in the current window
• history — Provides the History object for the window
• innerHeight — The inner height of a window’s content area
• innerWidth — The inner width of the content area
• length — Find out the number of <iframe> elements in the window
• location — Returns the location object for the window
• name — Sets or returns the name of a window
• navigator — Returns the Navigator object for the window
• opener — Returns a reference to the window that created the window
• outerHeight — The outer height of a window, including toolbars/scrollbars
• outerWidth — The outer width of a window, including toolbars/scrollbars
• pageXOffset — Number of pixels the current document has been scrolled horizontally
• pageYOffset — Number of pixels the document has been scrolled vertically
• parent — The parent window of the current window
• screen — Returns the Screen object for the window
• screenLeft — The horizontal coordinate of the window (relative to the screen)
• screenTop — The vertical coordinate of the window
• screenX — Same as screenLeft but needed for some browsers
• screenY — Same as screenTop but needed for some browsers
• self — Returns the current window
• status — Sets or returns the text in the status bar of a window
• top — Returns the topmost browser window

• alert() — Displays an alert box with a message and an OK button
• blur() — Removes focus from the current window
• clearInterval() — Clears a timer set with setInterval()
• clearTimeout() — Clears a timer set with setTimeout()
• close() — Closes the current window
• confirm() — Displays a dialogue box with a message and an OK and Cancel button
• focus() — Sets focus to the current window
• moveBy() — Moves a window relative to its current position
• moveTo() — Moves a window to a specified position
• open() — Opens a new browser window
• print() — Prints the content of the current window
• prompt() — Displays a dialogue box that prompts the visitor for input
• resizeBy() — Resizes the window by the specified number of pixels
• resizeTo() — Resizes the window to a specified width and height
• scrollBy() — Scrolls the document by a specified number of pixels
• scrollTo() — Scrolls the document to specified coordinates
• setInterval() — Calls a function or evaluates an expression at specified intervals
• setTimeout() — Calls a function or evaluates an expression after a specified interval
• stop() — Stops the window from loading

• availHeight — Returns the height of the screen (excluding the Windows Taskbar)
• availWidth — Returns the width of the screen (excluding the Windows Taskbar)
• colorDepth — Returns the bit depth of the color palette for displaying images
• height — The total height of the screen
• pixelDepth — The color resolution of the screen in bits per pixel
• width — The total width of the screen

• onclick — The event occurs when the user clicks on an element
• oncontextmenu — User right-clicks on an element to open a context menu
• ondblclick — The user double-clicks on an element
• onmousedown — User presses a mouse button over an element
• onmouseenter — The pointer moves onto an element
• onmouseleave — Pointer moves out of an element
• onmousemove — The pointer is moving while it is over an element
• onmouseover — When the pointer is moved onto an element or one of its children
• onmouseout — User moves the mouse pointer out of an element or one of its children
• onmouseup — The user releases a mouse button while over an element

• onkeydown — When the user is pressing a key down
• onkeypress — The moment the user starts pressing a key
• onkeyup — The user releases a key

• onabort — The loading of a media is aborted
• onbeforeunload — Event occurs before the document is about to be unloaded
• onerror — An error occurs while loading an external file
• onhashchange — There have been changes to the anchor part of a URL
• onload — When an object has loaded
• onpagehide — The user navigates away from a webpage
• onpageshow — When the user navigates to a webpage
• onresize — The document view is resized
• onscroll — An element’s scrollbar is being scrolled
• onunload — Event occurs when a page has unloaded

• onblur — When an element loses focus
• onchange — The content of a form element changes (for <input>, <select> and <textarea>)
• onfocus — An element gets focus
• onfocusin — When an element is about to get focus
• onfocusout — The element is about to lose focus
• oninput — User input on an element
• oninvalid — An element is invalid
• onreset — A form is reset
• onsearch — The user writes something in a search field (for <input="search">)
• onselect — The user selects some text (for <input> and <textarea>)
• onsubmit — A form is submitted

• ondrag — An element is dragged
• ondragend — The user has finished dragging the element
• ondragenter — The dragged element enters a drop target
• ondragleave — A dragged element leaves the drop target
• ondragover — The dragged element is on top of the drop target
• ondragstart — User starts to drag an element
• ondrop — Dragged element is dropped on the drop target

• oncopy — User copies the content of an element
• oncut — The user cuts an element’s content
• onpaste — A user pastes the content in an element

• onabort — Media loading is aborted
• oncanplay — The browser can start playing media (e.g. a file has buffered enough)
• oncanplaythrough — The browser can play through media without stopping
• ondurationchange — The duration of the media changes
• onended — The media has reached its end
• onerror — Happens when an error occurs while loading an external file
• onloadeddata — Media data is loaded
• onloadedmetadata — Metadata (like dimensions and duration) are loaded
• onloadstart — The browser starts looking for specified media
• onpause — Media is paused either by the user or automatically
• onplay — The media has been started or is no longer paused
• onplaying — Media is playing after having been paused or stopped for buffering
• onprogress — The browser is in the process of downloading the media
• onratechange — The playing speed of the media changes
• onseeked — User is finished moving/skipping to a new position in the media
• onseeking — The user starts moving/skipping
• onstalled — The browser is trying to load the media but it is not available
• onsuspend — The browser is intentionally not loading media
• ontimeupdate — The playing position has changed (e.g. because of fast forward)
• onvolumechange — Media volume has changed (including mute)
• onwaiting — Media paused but expected to resume (for example, buffering)

• animationend — A CSS animation is complete
• animationiteration — CSS animation is repeated
• animationstart — CSS animation has started

• transitionend — Fired when a CSS transition has completed
• onmessage — A message is received through the event source
• onoffline — The browser starts to work offline
• ononline — The browser starts to work online
• onpopstate — When the window’s history changes
• onshow — A <menu> element is shown as a context menu
• onstorage — A Web Storage area is updated
• ontoggle — The user opens or closes the <details> element
• onwheel — Mouse wheel rolls up or down over an element
• ontouchcancel — Screen-touch is interrupted
• ontouchend — User’s finger is removed from a touch-screen
• ontouchmove — A finger is dragged across the screen
• ontouchstart — A finger is placed on the touch-screen

• try — Lets you define a block of code to test for errors
• catch — Set up a block of code to execute in case of an error
• throw — Create custom error messages instead of the standard JavaScript errors
• finally — Lets you execute code, after try and catch, regardless of the result

• name — Sets or returns the error name
• message — Sets or returns an error message in a string from

• EvalError — An error has occurred in the eval() function
• RangeError — A number is “out of range”
• ReferenceError — An illegal reference has occurred
• SyntaxError — A syntax error has occurred
• TypeError — A type error has occurred
• URIError — An encodeURI() error has occurred